1. Field of the Invention
The present invention relates to a moving image encoding apparatus, a method, and a program and, more particularly, to a technique of subjecting moving image data of a high resolution to a parallel processing using a plurality of encoding units and multiplexing a plurality of bit streams obtained from the parallel processing to output as one bit stream.
2. Description of the Related Art
In recent years, owing to an advance of a digital signal processing, a large amount of digital information such as moving image, still image, audio, and the like can be encoded at a high efficiency to be recorded into a small recording medium or transmitted by a communication medium.
A moving image encoding apparatus which can convert a moving image obtained by a television broadcasting or photographed by a video camera into an encoded stream by applying such a technique has been developed.
Further, in recent years, in an image apparatus for business use or a large-sized television, a technique for further improving image quality has been proposed. For example, there has been proposed such a technique that a resolution of a screen size of an image signal is raised to a high resolution such as 4k2k, 8k4k, or the like which is further larger than that of the HDTV (1920 pixels×1080 lines) in the related art or a frame rate is raised to a high frame rate such as 120 Hz, 240 Hz, or the like.
However, in the case of performing an encoding processing to the image signal of the large screen resolution or the high frame rate, since an amount of information which is handled is suddenly increased as compared with the image signal in the related art, such a problem that an encoder of high performance which can perform a high speed processing is newly necessary occurs.
The following related art in which the above problem is solved and even if the image signal of the high resolution or high frame rate was input, an output of an encoded stream is realized by using the encoder in the related art has also been proposed.
In the Official Gazette of Japanese Patent Registration No. 04389883, such a construction that an image input of a high frame rate is distributed to a plurality of encoding units every frame, an encoding processing is executed in parallel, and a result of the encoding processing is output as one bit stream has been proposed. Specifically speaking, such a technique that the image input distributed to each encoding unit at a low frame rate is encoded in parallel in such a frame rate period has been proposed.
The apparatus has such a means that when encoded picture data which is output from each encoding unit is multiplexed to one bit stream, header information is updated so that a frame reference relation of each encoding unit is correctly held.
According to the related arts as mentioned above, even the input image of the higher resolution or higher frame rate than that in the related art, by processing it with a plurality of encoding units in parallel, a processing load accompanied with the encoding can be distributed.
However, in the Official Gazette of Japanese Patent Registration No. 04389883 mentioned above, although the parallel system can be realized by such a simple expansion of the encoding unit itself that the encoding processing is merely executed like a related art, there is a risk that the updating processing of the header information in a composition unit for outputting a bit stream becomes complicated.
On the other hand, performance cannot be optimized by such a design change that a plurality of continuous pictures are continuously encoded in accordance with a processing ability of each encoding unit.